Safety handle for air hoists



March 10, 1931. R. J. WILLIAMS 1,795,985

SAFETY HANDLE FOR AIR 'HOISTS Filed June 25.1927

ZI/ZZNZ mmmz J mZZLkzr/za mar Patented Mar. 10, 1931 UNITED STATES PTNT OFFICE 'RICI-IARI) J. WILLIAMS, OF VIRGINIA, MINNESOTA SAFETY HANDLE FOR AIR HOISTS Application filed'June 25,

lhe invention. pertains to a safety lock for a throttlelever and more particularly to a safety handle lockapplied to the throttle of an air hoist or winch.

In the service operation of a winch or hoist, a rope is applied to the drum, the loose end of which is attached to the device to be moved. In some instances this device is a small road scraper and by this means ore is l transported short distances from the place where it is blasted down, and thence led into chutes to tram cars. One man controls the handle of the scraper and only one man is V needed to operate the hoist. With some designs of hoists, the throttle lever, when open,

will stay in any position in which it may be when the hand is removed from it, and in most hoists, this throttle lever can be accidentally knocked into open position if it is hit by some external force. It will be understood, of course, that this frequently results in accident due to the hoist starting when men are in dangerous positions relative to the scraper or have their hands on a moving )art. 1 It is therefore an object of this invention to provide a locking handle for a throttle-lever which cannot be accidentally movedto cause operation of said throttle lever.

Another object is to provide a throttle of such character that it will automatically return to inoperative position if the handle is released.

Still another object is to provide a simple, effective yet inexpensive locking and returning means for a throttle lever.

A. further object is to provide a safety device which may be readily applied to existing machines as well as to machines initially pro vided with such device.

Other, various and more specific objects will readily occur from the specification,

claims and drawings appended hereto.

In the drawings, wherein like reference characters are used to designate like parts Figure 1 is a side elevation of a winch or hoist having the safety handle applied thereto; Figure 2 is an end elevation of the motor 192?. Serial No. 201,303.

housing of the winch, showing the safety handle in locked position; and c Figure '3 is an enlarged sectional view, showing the relation of the parts of the throttle handle, the'handle being in locked position. I

A usual winch 10 of the tugger type is illustrated, being bolted or otherwise secured by bolts 32 to a base 11. This winch is provided with a drum 12 having the winding rope wrapped thereon, which drum is operated through the clutch mechanism 13 by a motor provided in thehousing 15. Brake mechanism 14 is also provided for checking thelmovement of the drum. The throttle lever is indicated at 16 integral withor fastened to a pivotally mounted operating valve cylinderl'Z. lhe throttle valve handle comprises a member 18 fastened directly to the cylinder 17 and extending into the operating handle 19. A shoulder 22 is provided on the end of the member 18 extending'into the handle 19 and a spring 20 surrounds the member 18 and is disposed between the shoulder 22 and the apertured base 21 of the handle and tends toforce theshoulder 22 towards an end 34: of the handle. Or, in other words,

tends to force'the handle 19 towards a stationary locking member provided on the housing 15.. This handle is provided with a locking projection 23 extending through a guide 24 on the member 18, and in normal po# sition cooperates with a hole or aperture 35 provided in the locking member 25. It will be seen that'this member 25 is provided with a base 26 which is fixed to the motor housing by any means, such as the bolts 31 which may also fasten'the housing to the hoist. The

member 25 is also provided with a cam portion 27 disposed in way of thepath of rotation of the member 23. lhis cam portion may. be provided with'an attaching arm or lug 29 fastened to any upstanding member 30 of the motor housing by'means of the bolt 28.

It will be understood that in normal position, that is, the locked position, the throte tle lever is in the position indicated in Figure 2, that is, with the projection 23extending into the aperture 35. In operating the motor,

it is then necessary to pull the handle in a direction away from the locking member 25. That will compress the spring and remove member 23 from aperture 35, allowing the throttle lever to rotate the valve cylinder 17, it being understood that the plunger 23 tends to move toward the cam 27 by the influence of the sp 'ing. If the throttle is in open position and the handle is released, the plunger 23 will be urged toward the cam 27 by the spring 20 and the cam is so shaped that the spring will cause the plunger to travel along the cam face until it reaches the aperture when it will enter said aperture and lock the throttle in inoperative position, cutting off the power to the motor. Due to the lock, it will be seen that if the handle is accidentally struck, it cannot cause the motor to start as the throttle will not move due to the cooperation between member 23 and the aperture 35. This member is then doubly safe as it cannot he accidentally operated, and if released while in operation, it will automatically seek an inoperative position.

It will be understood that this handle is not only applicable to a hoist or winch as it may be applied to any other valve operating or throttle mechanism, and it will be seen that other and various forms of the device will occur to those skilled in the art so I do not wish to be limited by the embodiment shown, which is only by way of illustration and not by way of limitation.

I claim:

1. In a device of the character described,

- the combination of a fixed locking member, a

pivoted control member normally locked in inoperative position, said member including a projection, a handle cooperating with and movable with respect to said projection and having a locking member thereon cooperating with said fixed locking member, a cam leadins to said fixed loclzin member and resilient means cooperating with the handle to urge the locking member along the cam surface and into locking 30Slill011.

2. In operating mechanism for hoists or the like the combination of a throttle including a plurality of relatively movable members, one oi said members being a hand grip and cooperating with said other member, a resilient member-disposed between said members for urging said grip into a predetermined position, a projection disposed on said grip member, a cam member disposed adjacent said throttle and adapted to be contacted by said projection, a stop on said cam adapted to be contacted by said projection when said throttle is in predetermined position, said resilient member urging said projection toward said cam and causing said projection' to be urged toward said stop.

In a device of the character described, the combination of a fixed cam member, a rotary operatingm-ember, a projection thereon extending into an operating handle, a projection on said handle for locking said operating member in inoperative position, resilient means on said first mentioned projection for urging said second projection into locking position, said second projection cooperatingwith said fixed cam member when said operating member is rotated to operative position to thereby tend to cause said operating member to move to inoperative posi tion.

Signed at Virginia, Minnesota, this 18th day of June, 1927.

- RICHARD J. lVILLIAMS. 

